1. Field of the Invention
This invention relates to ditching operations and in particular to the forming of ditches with desired profile, and to cleaning existing ditches of multiple profiles.
2. Description of the Background Art
Current ditching operations employ the use of either heavy equipment equipped with a scraping blade or a bucket, or of rotating drum(s) that are mechanically or hydraulically driven and supported by a carrier. The rotating drum(s) ditching machines are considered an improvement when compared to the blade or bucket carrying equipment due to their speed and low cost operation. This invention belongs to the rotating drum(s) ditching machines, which are hereby considered "prior art". The prior art employs one or more drums of cylindrical or conical section that accomplish a ditch of a fixed trapezoidal profile. Harder grounds require narrow ditches, while softer grounds require wide ditches with gradual slopes to reduce the possibility of the bank walls collapsing. Shallower or wider ditches are achieved by multiple passes of the ditching machine over the same stretch of ditch, while positioning the rotating drum(s) at different transverse or angular positions. Since deep ditches with bank inclination 1:1 or steeper are not considered capable of supporting vegetation growth, shallow ditches with a bank inclination 2:1, 3:1 etc. are becoming more desirable recently due to environmental reasons.
One known trencher (U.S. Pat. No. 4,535,555) provides multiple ditch profiles by having adjustable inclination wheels, but it is intended for off-road use since it throws ditch material on both sides and due to its weight, complexity, and power requirements, is powered and supported by a large off-road carrier.
The prior art stands in need of considerable improvement with regard of providing a simple, lightweight roadside ditching machine, that produces the desirable ditch profile in one pass and discharge the excavated material either to the far side, or to the road side of the ditch for later pick-up.
3. Summary
The present invention comprehends an improved method and apparatus for cutting and/or cleaning ditches of multiple profiles, employing one rotating drum of conical-cylindrical section. This drum is positioned to accomplish the desired ditch profile by rotating its supporting frame against a fixed frame that is attached to the carrier. By rotating the supporting frame around the vertical axis the multiple ditch-profiles are achieved. The transmission of mechanical power at all drum positions is attained by the cooperation of two right angle gearboxes, one of which is fastened to the fixed frame while the other onto the rotatable frame. One through driveshaft is connecting the gearboxes at all angles and one remotely controlled hydraulic cylinder positions the rotatable frame. The power transmission to the drum is completed by a gear, chain or belt transmission depending on the required horsepower and drum size. The rotating drum is positioned to its various working positions by means of articulation as shown in the attached drawings.
It should be noted here that different slopes (e.g. 1:1, 2:1 etc.) can be cut by using different cross sectioned drums.